Earth Sciences 1023A/B Lecture Notes - Lecture 1: Subatomic Particle, Relative Atomic Mass, Atomic Number
18 Apr 2019
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Document Summary
Basically just using powers of 10 to simplify. Philosophers proposed that matter was made up of tiny, indivisible particles in constant motion. All atoms of 1 element have the same size and weight. Atoms of elements unite chemically in simple numerical ratios to form compounds. The electron was discovered (negatively charged subatomic particle) Thompson used this electron theory to create the plum pudding model for the atom. Rutherford explained an atoms structure as positively charged nucleus with negative electrons orbiting it (think of gold foil experiment) Bohr used quantum theory to explain why electrons could remain in certain orbits without radiating energy (they had speci c orbits and energy elds) Element= a single or isolated group of particles composed only one species of atoms. Atom= the smallest unit of matter that possesses the properties of an element. Composed of subatomic particles (protons, neutrons and electrons) Protons and neutrons are found in the nucleus (make up for most of the mass)
